What about the Physical and Chemical BIOTIC factors? I am really stuck on that one. I have just started Yr 12 Biology and am now doing Ecology. So any great tips on how to tackle this topic would be grand. Thank You....

Biotic? If I undestud right, you mean how biota effected the water ballance? I think that most significant think - it is delay water at the soil espessially by plants roots. So evaporation from land become more large and reins distribution is influenced. Another think that can follow from this delay - it is many relative small and shallow lakes formation at the north regions, like Canada, Finland, north Russia.